Kerry parish records are online at www.irishgenealogy.ie
I looked for the baptism of a John OConnor/Connor in Tralee in
in 1855 and there at least three possible. Link http://tinyurl.com/at5qpkq
Without knowing father's name at least it would be almost impossible to confirm which is the correct one. There is no Clarke/Connor marriage showing but as Julia was from Co Clare it is possible the marriage took place in Clare. Can you access the Us census as in the 1910 census there is a O Connor family in Sellick St Stamford John b. Ireland 1855 occupation contractor wife Julia b. Ireland. John immigrated 1870 and married c. 1876 so they were married in the US possibly Connecticut as the children were born there.They had 8 children 6 alive in 1910
Mary 33 Nellie 31 Julia 28 Delia 22 and James T aged 24 - the 6th child is not there and could be John Clarke O Connor
away from home. Do you have the death certificates for John and Julia as these may give their parents names - I am not familiar with Connecticut death certs and what details they give.
In the 1920 Census the four daughters are living at the same address no record of Julia- but if this is the correct family she was dead by then - nor of John Snr.
Hope this is of some help.